SPT

South Pole Telescope

These files contain South Pole Telescope (SPT) temperature maps of the approximately
95-square-degree ra5h30dec-55 field observed during the 2008 season in the 150 GHz and 220 GHz
bands, produced for the first SPT data release in December 2011. The 150 GHz map combines
approximately 621 hours of observations with a median number of 304 individual bolometers
contributing data during each observation. The 220 GHz map combines approximately 605 hours of
observations with a median number of 166 detectors contributing data.

Maps are provided using the oblique Lambert equal-area azimuthal projection and the
Sanson-Flamsteed projection.

The maps in the oblique Lambert equal-area azimuthal projection have 0.25 arcminute map pixels
covering a 3120-pixel by 3120-pixel grid. These maps are stored in the primary image arrays of FITS
files. The center of the ra5h30dec-55 field is at R.A. 82.70247 degrees and decl. -55.00076
degrees.

The maps in the Sanson-Flamsteed projection have 0.25 arcminute map pixels covering a 3120-pixel
by 3120-pixel grid. These maps are stored in the primary image arrays of FITS files. The center of
the ra5h30dec-55 field is at R.A. 82.70247 degrees and decl. -55.00076 degrees. The center of the
coordinate system used for the Sanson-Flamsteed projection (as indicated by the CRVAL1 and CRVAL2
keywords) has a declination of 0 degrees.

The maps were constructed by a simple inverse-noise-weighted averaging of calibrated
time-ordered-data from SPT bolometers over many observations of the field. The units of the maps
are K-CMB, expressing deviations from the average measured intensity as equivalent fluctuations in
the CMB in Kelvins. The combined weights computed for each map pixel are stored in
associated FITS files.

Time-domain filtering of the raw data is used to deconvolve the detector time constants, remove
noise on scales smaller than the pixel scale of the maps, and remove atmospheric noise.

For the maps in the oblique Lambert equal-area azimuthal projection, bright emissive sources in
the field have not been masked in the filtering. This results in visible "ringing" around the
locations of bright sources in the maps.

For the maps in the Sanson-Flamsteed projection, bright emissive sources in the field have been
masked in the filtering to prevent "ringing." The sources masked in this release are those
detected at greater than 5 sigma significance in either frequency band from the analysis presented
in Vieira et al. 2010, ApJ, 719, 763. The brightest 9
sources in that list are masked to a radius of 5 arcminutes, and the rest are masked to a radius
of 2 arcminutes.